Electric control system for conveyers



y 3, 1932- J. SYLVESTER 1,856,669

ELECTRIC CONTROL SYSTEM FOR CONVEYERS Original Filed Jan. 21, 1929 12Sheets-Sheet l May 3, 1932. J. SYLVESTER 1,856,659

ELECTRIC CONTROL SYSTEM FOR CONVEYERS Original Filed Jan. 21, 1929 12Sheets-Sheet 2 gwoentot duo: vu q May 3, 1932. J. SYLVESTER ELECTRICCONTROL SYSTEM FOR CONVEYERS Original Filed Jan. 21, 1929 12Sheets-Sheet I5 6 66696 Q khaxm Jam WM.

May 3, 1932. J. SYLVESTER ELECTRIC CONTROL SYSTEM FOR CONVEYERS l2Shets-Sheet 4 Original Filed Jan. 21, 1929 May 3, 1932.

J. SYLVESTER 1,856,669

ELECTRIC CONTROL SYSTEM FOR CONVEYERS 12 Sheets-Sheet 5 Original FiledJan. 21, 1929 J. SYLVESTER May 3, 1932.

ELECTRIC CONTROL SYSTEM FOR CONVEYERS Original Filed Jan. 21, I929 12Sheets-Sheet 6 Q 501003.75 HI JN/l ELECTRIC CONTROL SYSTEM FOR CONVEYERSl2 Sheets-Sheet 7 Original Filed Jan. 21, 1929 gwuenl ov 6cm mg May 3,1932.

J. SYLVESTER ELECTRIC CONTROL SYSTEM FOR CONVEYERS 12 Shets-Sheec 8Original Filed Jan. 21, 1929 y 1932 J. SYLVESTER 1,856,669

ELECTRIC CONTROL SYSTEM FOR CONVEYERS Original Filed Jan. 21, I929 12Sheets-Sheet l0 Qwoentoc y 1932. J. SYLVESTER. 1,856,669

ELECTRIC CONTROL SYSTEM FOR CONVEYERS Original Filed Jan. 21, 1929 12Sheets-Sheet ll May 3, 1932. J. SYLVESTER I 1,856,559

I ELECTRIC CONTROL SYSTEM FOR CONVEYERS Original Filed Jan. 21, 1929 12'Shee ts-Sheet 12 MIIIIIIIIIIIIIIIII Patented .May 3, W32

annrns srrvnsrm,

ernnnarnecorarenr, nnnawaan ori inal application filed awa a1, 1929,

January 4, 1930.

This invention relates to an electric control system for conveyers," andthe present application'is a division of my prior application filedJanuary 21, 1929, Serial No.

In my said application Serial No.v333,887 l have showntheielectric-control system of the present invention as applied forcontrollingithe' action ot'sets-of ,conveyer rolls of as a roller leerform ng partotaz-sheet glass forming and annealing kapparatus in whi'call the rolls rotate at ahigh speed, which may be equal to the rateofsheet formation, and in which, by means of the said electrical con 1Etrol system, a portion of the rolls normally.

I normally rotating rotate constantly forward while another por-. tionof the rolls are caused to rotate periodicall and successively forwardand backwar so that the progress of the intermit-. tently formed sheetsof glass through the leer as a whole is substantially slower than thefeed rate of the first-named rolls, or the rate of sheet formation. Asdisclosed in said application Serial No. 333,887, the leer rollspreferably comprise a primary set of rolls constantly forward to conveythe sheets on a preliminary traverse at a. high rate of speed, asecondary set of reversing rolls driven at a rate of speed at least asgreat as that of the primary are periodically reversed so. that theywill periodically impart a 'diiijerential backand the sheets onltheirfinal.

forth movement to traverse suchthat the sheets progress at a less theirpreliminary traverse, and an intermediate setpf transfer rolls whicharealternately rotated backward and forward and synchronize successivelywith the primary and reversing sets of rolls for the transfer of thesheets p from the primary set to of rolls without buckling of thesheets; the arrangement being such that the sheets are supported byconveyer rolls rotating throughout at a constant high speed to preventdeformation of the glass while governed in part with respect todirection of rotation to cause the sheets to takea course of travel ofgreater length and greater duration of time than required by a directtravel of the sheets Serial at. 333,887. Divided and.

Serial No. 418,576.

set but which d placed directly upon the reversing set rates OFWASHINGTON, PENfiSYiJVANI-A, ASSIGNOR T0 SIMPLEX EN- OF WASHINGTON,PENNSYLVANIA, A CORPORATIQN 0F nnncrme contract. 'srsrnia FOB convrnznasthis application tiled speed. The rolls may also by means of theelectrical control system be governed to reg ulate their reversingperiods, and the rolls may further baa-arbitrarily caused in whole or inpart 'to rotate forward or backward at will to meet varying conditionsof service.

The present invention applies to the broad use of a control system ofthecharacter described in conjunction with a roller or equivalent conveyerfor general purposes in the transportation of goods or articles ofvarious kinds through a treatment kiln, chamber or course, where thegoods or articles during the treatment period should have a range oftravel greater than the length of the kiln, chamher or course. Thepresent invention, therefore, is not limited to the use of a controlsystem in conjunction with a glass forming apparatus employing a rollerleer in which the working action of the control system and rolls isdependent upon the intermittent action or sheet formation rate of aconjoined sheet forming device, or to the feed. and treatment by theapparatus of sheet glass, or to the feed of the material constantlyforward on the initial part of its travel at a fast rate of progressionand thereafter at a lower rate of progression, as the control system androller conveyer or itsequivalent may be used for potion on glass sheetsformed by a sheet forming device separate from, a conveyer mechanism orleer,'or for action upon sheet materials of other kinds, or upon bars,bil-- lets or other articles to be variously treated, or for actionupon' glass, porcelain orjother articles or ceramic goods generallyeither the conveyer or upon; trays or other liolders fintermittently suplied for transport by-the conveyer through the leer treatment kiln,chamber or course. The present invention is, furthermore,not limited toan apparatus in which a primary portion of the rolls constantly rotatein a forward direction and succeeding rolls are periodically andsuccessively reversed torotate alternatelyforward and backward, as;within the spirit and'scope of the invention, the action of'the rollsmay be opposite of; that described, or,-in other words, the pri- 1 tillmary portion of the rolls may be those reversed for periodic forward andbackward motion and the succeeding rolls have a constant forward motion,so that the articles may have a slow rate of progression on thepreliminary part of their travel and a faster rate of progression on thefinal or following part of their travel.

The invention is shown in the accompanying drawings as employed inconjunction with a' treatment kiln or chamber in the form of a glassannealing leer including, a roller conveyer, but it is to be understoodthat the invention is not restricted to the particular structures shownfor purposes of exemplification, but may be employed in conjunction withany of the various types of treatment kilns or chambers and conveyersfor which it is adapted.

Tn the drawings Fig. 1 is a diagrammatic side elevation of a kilnembodying a roller conveyer in connection with which my improvedelectrical control means is used.

Fig. 2 is a vertical transverse section through the kiln, showing thedriving mechanism for one of the rolls.

Figs. 3 and 4 are diagrammatic views showing the progress of a sheet ofglass through the first portion of the kiln.

Fig. 5 is a side elevation of one section of the kiln showing one of theroll operating shafts.

Fig. 6 is a wiring diagram of the electrical conveyor controlling means.

Fig. 7 is a graphic representation of the normal progress of a sheet ofglass through the kiln.

Figs. 8, 9 and 10 are diagrammatic representations of the roll drivingapparatus.

Fig. 11 is a detail view partly in side elevation showing the clutchoperating mechanism.

Fig. 12 is a View partly in section and partly in plan showing theclutch operating mechanism.

Fig. 13 is a horizontal sectional view of the clutch assembly on line13-13 of Fig. 14.

b Fig. 14: is an end view of the clutch assem- Figs. 15, 16 and 17 aredetail views on an enlarged scale showing the emergency control device.

Figs. 18 and 19 are enlarged details showing one of the master controls.

While in the following description the invention is set forth moreparticularly with relation to a roller leer as the treatment apparatusand to sheets of glass as the material conveyed and treated, it is, ofcourse, to be understood, as before stated, that the particularexemplification given is merely used for convenience, and that theinvention is not in any manner restricted thereto.

The leer, kiln or treatment chamber, defining the treatment course, isindicated diaan open portion 18 along which the sheet of gliiSS 16 isadvanced by means of rotating ro lers 17 to the closed or chamberedportion L of the leer. Suitable doors (not shown) may in practice heprovided at this end of the leer, which may be opened to permit thesheets as they are fed up to pass into the leer, the doors then beingclosed to prevent loss of heat from the leer. The closed or chamberedportion of the leer may be heated by suitable electrical or otherheating means, and this portion of the leer may be made up of twoprincipal divisions which may be referred to as the highly heatedportion 19 and the less highly heated portion 20. The temperatureswithin the leer chamber may be regulated as desired, but preferablyrange from a maximum of about 1200 F. at a point near the entrance tothe highly heated portion of the leer, to a temperature of about 150 F.at the end of the cooling portion of the leer, the temperatures more orless gradually decreasing etween maximum and minimum, as indicated inthe diagrammatic showing in Fig. 1. The operation of the conveyinrollers 17 in conveying the glass sheets t rough the leer will bedescribed in greater detail hereinafter in reference to the controlmechanism. Briefly set forth, however, the glass sheet passes first ontoa series of rolls rotating in a forward direction only at apredetermined high speed, which may, as set forth in my applicationSerial No. 333,887, in the case of the use of a conjoined glass sheetcasting apparatus, be at least as great as the speed of sheet formation,while the rolls in the principal portion of the leer are revolvingsuccessively forwardly and then rearwardly, but at a peripheral speed atleast as great as I that of the rolls which move forwardly only.

These alternately reversing rolls normally rotate in a forward directionfor a longer period than in the rearward direction, or, in other words,have difierential forward and backward feed motions, in order that theremay be a general advance of the sheet through the leer as a whole. Inorder for the sheet of glass to pass from the forwardly moving rolls tothe reversing rolls it is necessary to provide an intermediate set oftransfer rolls to prevent buckling or breaking of the sheets of glass.These transfer rolls take up first the movement of the first orforwardly moving rolls until the sheet of glass rests entirely upon thetransfer rolls. The transfer rolls grammatically in Fig. 1, andcomprises first Elli) are then automatically synchronized with the.

- tershafts by Fig. 6). This automatic synchronism is accomplished bywith switches 79 and 81 in a circuit 80, as shown in Figs. 3 and 4, andas will be more fully described hereinafter by reference to the controldiagram in Fig. 6.

In passing'from the closed portion L of the leer the glass is receivedupon idler rolls The rolls 22 may be operated by a motor 64,

Fig. 10, which drives the rolls through a chain 83, shaft-84 and wormgearing 85, the motor being started and stopped by means of a suitablehand switch (not shown). In this manner the glass sheets may betransferred from the leer to the rolls 22 and the rolls 22 then stoppedby cutting off the motor 64.

The general arrangement of the roll driving mechanism is shown in Figs.2 5, 8, 9 and 10. The rolls of each section in the main portion of theleer are driven by shafts 51, Fig. 5, near the center of each of WlllCll1s locateda sprocket 52 which is turned by a chain 52 passing oversprockets 53, 54, Fig. 2, carried by a main shaft 55 and a countershaft56 respectively. The sprockets 53 and 54 are caused to rotate witheither the main or counmeans of clutches 58, 58*, shown in detail inFigs. 11, 12 and 13, which clutches are operated bysolenoids 57. Asshown in- Fig. 8, the main shaft 55 extends the entire the countershafts56 being at 56*, and rotating in a to the main shaft. The main shaft isdriven from a plurality of motors 59 and 60 geared thereto, and havingpin clutches interposed between the motors and the shaft, whereby anyone of the motors may be removed for repairs without interfering withthe operation of the leer (Fig. 8).

In Fig. 8 portions of the leer are represented diagrammatically. Themain shaft extends the entire length of the leer proper beginning withthe open section 18 and ending at the .end of cooling section 20. Thisshaft isconstantly rotating and all the rolls of the leer proper areoperated from this shaft over one of the countershafts, at a constantperipheral speed equal to the speed of sheet formation. The direction ofmotion will be either forward or rearward dependlength of the leer,geared thereto as direction reverse ing on whether the rolls areoperated direct- 9 1y from the main shaft or from the countershaft. Themain shaft does not extend along section 21 as this 'section'is occupiedby the idler rolls and the rolls 22 at the discharge end are notactuated from the main shaft but contact of the glass sheets.

' stood that one set of clutches from the shaft 53 by means of the motor64, as previously described.

The clutches and clutch operating mechanism which serve to connect eachroller shaft 51, which drives a section of rolls 17, alternately to themain shaft 55 and to the countershaft' 56 to thereby rotate the rollers17 of one section of the leer alternately in a forward and rearwarddirection are best shown in Figs. 11, 12, 13 and 14. It will be underandoperating mechanism therefor is employed for each set or section ofrolls except the first, and the description of one such mechanism'isapplicable to a 1.

As shown the main shaft 55 is constantly geared to the countershafts 56and the sprockets 53 and 54 are loosely mounted upon these rotatingshafts, but each rotate with its respective shaft by means of theclutches 58 and 58". These clutches are provided with pins 100 which areengaged by fingers 101 of the crank arms 102 carried by a shaft 103journaled at its ends in bearings 104. The shaft 103 is rotated by meansof may be caused to.

an arm 1 04 of a bell crank, the other arm 105 of which is engaged bythe spring 106 which tends to operatethe clutch 58 upon the mainshaft55; so that when no power is applied to the arm 104 of the bellcrank the rolls of this section of the leer will be operated from themain shaft and in a forward direction. v

The arm 104 of the bell crank is operated by the solenoid 57 in suchmanner that when the arm 104 is depressed the clutch 58 causes thesprocket 54 to rotate with the counter shaft-56 and thus produce reverserotation of the rolls of the section controlled by this solenoid.

As' shown in and the clutch operating arm 18 as follows: The core 107 isconnected by means of a universal joint 108 to a compound plungerreciprocable in a cylinder 109. The compound plunger is composed of anouter plunger 110 and an inner plunger 111, the latter being directlyconnected to the core of the solenoid, and slidable within a housing112, of the outer plunger. A spring 113 reacts between the inner plungerand the housing 112. The outer plunger is connected through crank arms114 passing through slots in the cylinder 109, to an adjustable link115, which is carried by clutch operating arm 104. The forked member 114is pivoted intermediate its ends and is suspended by means of a swinging116 to a fixed frame member 117.

Below the cylinder 109 is a dash pot or retarder 118 which isfilled withoil or the like under pressure. A piston 119 works in the dash pot andis connected to plunger 110 by means of a piston rod 120. A by-passconnection 121 opens above and below the piston 119, which bypass may becut off to any desired extent by means of a screw operated valve 122. Inthis manner the action of the piston 119 and of the plunger 110 may beretarded to any desired extent.

The purpose of the retarding action of the dash pot is to prevent jarsdue to sudden reverse of direction of rotation of the rolls, which mightcause breakage of glass. By the use of the retarder the reversal isgradual and without shock.

As shown a finger 123 projects'into the cylinder 109 and is engaged bythe plunger 110 in either direction of its movement. The finger 123controls a circuit in which is located a signal light which is designedto indicate to the operator of the leer whether a particular solenoid isin operation. A plurality of such signal lights are shown at 124 in thecontrol diagram, Fig. 6.

The solenoid 57 is alternately energized and deenergized by means of amaster control switch or timer 125, which timer may through a suitablearrangement of relays and main operating circuits control all of thesolenoids of all the roll sections. As shown the timer comprises a dialupon the face of which is located a conductor portion 126 and aninsulating portion 127, the two portions making up a complete circle. Arotary contactor or hand 128, which is preferably operated by suitablegearing from the main drive shaft of the leer, engages alternately theconducting portion 126 ofthe dial, and then the insulating portion 127.During the period of engagement with the conducting portion a circuit isclosed through the solenoid, which draws the core 107 upward, and withit the inner plunger 111, which serves to compress spring 113. Thespring 113 moves the plunger 110 upwardly, with a delayed action due tothe dash not 118. The upward movement of the plunger 110 depresses arm10 1 of the clutch operating mechanism against the resistance of spring106 and causes the sprocket 54 to rotate with the counter shaft 56, thusproducing reverse rotation of the rolls in th section controlled by thesolenoid.

As soon as the contactor arm 128 reaches the insulating portion 127 ofthe control dial the circuit to the solenoid is broken and an actionopposite to that just described takes place, and the section of rolls ofthe leer which had been rotating in a reverse direction are now rotatedin a forward direction by the main shaft.

The timer switch is shown in further detail in Figs. 18 and 19. In Fig.19 the numeral 129 denotes a gear wheel which is operated through worm130 and suitable intermediate mechanism from the main drive shaft 55 ofthe leer for rotating the contactor arm 128.

By regulating the relative lengths of the conducting strip 126 andinsulating strip 127 the relative periods of reverse and forwardmovement of the rolls can be varied at will. Thus, with balanced gearratios, if the two strips were of equal lengths the rolls would rotateforwardly and rearwardly for equal periods of time, and there would beno progress for a sheet of glass on such rolls. In the normal operationof the leer the insulating portion of the dial is longer than theconducting portion; thereby the rolls rotate for a greater periodforwardly than rearwardly, and there is a gradual advance of the glasssheet through the leer. It is also possible to cause a general reversemovement of the glass by having the conducting portion of the controlswitch longer than the insulating portion. It is also possible to causeall the rolls to rotate continuously forwardly or continuouslyrearwardly by having the arm 128 contact with insulating material only,or with conducting material only. A regulation of the relative effectivelengths of the conducting and insulating strips may be accomplished bymeans of a hand wheel 131 which rotates a gear 132 in mesh with atoothed wheel 133, which serves to regulate the length of time ofcontact between the arm 128 and the insulating and conducting strips 127and 126 respectively.

The toothed wheel 133 is connected to an insulating block 200 whichlatter is connected by means of screws to an insulating block 201. Theblock 201 has a helical groove 202 to receive the conducting strip 126which is in the form of a helix, one end being fastened to a stationarypart of the leer, for example, by the bolt 203 whilst the other end isfree. By rotating the insulating block 200 by means of the gears 132,133 the helical conducting strip can be wound into the interior of theinsulating block and thereby expose the free end to the desired degreedepending on the amount of rotation given to the gears.

Turning the gears in one direction will expose a greater amount of thehelical conducting strip, while turning them in the opposite directionwill expose a lesser amount of the strip.

In Fig. 6 two master control switches or timers, A and B are shown, suchas that designated by 125 and described in reference to Fig. 11. Theseswitches are connected to a positive source of current by means of leads150 and 151, while the contactors 128 are connected to a negative supplyby means of leads 152 and 153. Leads 154 and 15st are provided by meansof which additional circuits are closed leading to emergency controlswitch C through relays 155 and 155. The details of the emergencycontrol switch are shown in Figs. 15. 16 and 17. This emergency controlconsists of an annular member comprising two conducting halves 156, 157separated by insulating blocks 158, 159. The annular member may berotated by means of a handle 160 so as to bring the insulating blocks toany desired position. Contact mag be made between master switches-A andand the emergency control C by means of fixed contactor fingers 161 and162, which may be connected with either section 156 or 157 of theemergency control. In addition to the main contact fingers 161 and 162there are a plurality of smaller contact fingers 163, each of whichcontrols a circuit through one of the solenoids 57. The number of thecontact fingers 163 is equal to the number of solenoids, which in turnis equal to the number of roll sections to be controlled. Manuallyoperated switches 164 are interposed in each solenoid circuit so thatany one of the sole noids may be cut out by opening its switch 164. Itwill be observed that the timer switches A or B operate to causepulsations of relays 155,.155 and 143 whereby the relays '143 arealternately energized and deenergized to close and open main operatingcircuits for the solenoids 57 from the main leads 143, 143'. Such a mainoperating circuit is represented, for example, by wires 168, 168',

- the latter containing a relay switch 143 energized and deenergized bythe closing and opening of circuits including the conductors 150, 152and 151, 153 by the action of the switches A and B.

A typical'circuit from the emergency control device C through thesolenoids is represented by the last solenoid circuit at the right ofthe control device, leading from contact fin ers 163 through wire 165,finger switch 164, wires 166, 167, relay 143 and wire 168 connected toline 143, solenoid 57, thence through wire 168 back to the line 143'.The

lines through the other contact fingers arethe same except that thefirst nine lines at the left, or any desired number of lines, areprovided with auxiliary control switches 145, 146, actuatedautomatically from the switches 79 and 81, which in turn are operated bythe movement of glass through the leer. as previously described brieflyin connection with the description of Figs. 3 and 4. These auxiliarycontrol switches 145 and 146 are in addition to the controls in theremaining circuits. When these auxiliary controls are closed thecircuits from the emergency control through the solenoids of the firstnine lines at the left are identically the same as the circuits for theremaining sections, previously described. When the switches 145' and 146are open no current is supplied to the solenoids of the first ninelines, and consequently the rolls of the sections controlled by thesesolenoids are rotating constantly forward. The switch 145 controlsthefirst seven solenoids, and the switch 146 the-eighth and ninthsolenoids.

By the use of the emergency control device all the contact fingers 163and, consequently, all the solenoids may be placed in circuit withmaster control A, this arrangement being that shown in Fig. 6. Byturning the handle 160 ofthe emergency controlslightly to the left sothat the insulating blocks w1ll be moved just beyond the main switches161 and 162 all the solenoids ma be placed in circuit with mastercontrol The master controls may be set for any desired operation of therolls by regulating the relativelengths of the conducting andnonconducting portions of the dials as previously set forth. Instead ofconnecting all the lines to one master switch A or B apart of the linesmay be connected to one switch, and part to the other master switch bysetting one of the insulating blocks 158 or 159 of the emergency controldevice at a. point intermediate the ends of the row of contact fingers163. Thus by placing insulating block 158 at the finger contactindicated at D the sole- I101(l 1n the particular line-leading from thiscontact will be cut out of operation. The l nes to the left of positionD will then be in circuit with master control A, while those to theright will be incircuit with master control B. Assuming that control Ais set to produce equal forward and reverse rotation of the rolls andcontrol B is set to produce a general forward movement it will be seenthat by the above described operation sheets of glass in rear of asection of broken glass could be prevented from advancing and thusdestroying the good sheets, while the sheets of glass in advance of thedefective section could be caused to move uninterruptedly out of theleer. Obviously, innumerable other modes of operation may be employeddepending on emergencies which may arise under actual serviceconditions. Complete control of all sections of the leer may be had bythe arrangement herein described.

It is desirable that in case of failure of any one of the solenoids tooperate, this fact may at once be brought to the attention of theoperator. For this purpose the signal lights 124 are provided which, aspreviously set forth, are controlled by switches operated by theplungers of the solenoids so that in case one solenoid is notfunctioning the corresponding light 124 will go out.

While the leer is capable of flexible operation and emergency control,as above described, the normal operation is that illustrated graphicallyin Fig. 7, in which the movement of the glass in feet is designated bythe abscissa at the top of the sheet, and the time in seconds isillustrated by the vertical numerals or ordinates.

In the figure the line M N is intended to represent the movement of thefront end of a sheet of glass passing through the leer, the portion M ofthe line indicating the initial forward movement on the primary andtransfer rolls of the leer, while the portion N indicates theintermittent forward and rearward movement in passing through the majorportion of the leer. The movementvof the rear end of the sheet of glassis indicated by the second line 0 P, while the third line Q Rillustrates a portion of the path of the front end of a second sheet ofglass. It will be noted that the path of the rear end of the first sheetof glass and that of the front end of the second sheet merge at S, andthat from there on the movement of the two sheets through the leer issynchronized. The successive sheets are started at determined intervalsof time, as indicated by the graph, but by the time the sheets enter themain portion of the leer and take up the alternate forward and rearwardmovement they occupy practically the entire space in the leer, the frontend of one sheet reaching practically to the rear end of the sheet infront of it. In this manner the leer is operated with the ut mostefficiency. Moreover, the alternate forward and rearward movement of theglass gives the effect of a much longer leer than that actuallyemployed, i. e-., a travel range for the glass sheets between theentrance and exit ends of the leer, which is of a distance greater thanthe length of the leer, and much more efficient annealing than ispossible with any other device, is obtained.

The normal operation of the leer will now be described in connectionwith the wiring diagram, Fig. 6.

As previously set forth the leer is composed of rolls arranged in aplurality of-sections. All the roll sections except the first section,are controlled by individual solenoids, the operation of which hasalready been described.

Reference will now be made to the control of the leer as a whole,including all the sections of rolls from the second sectionto the end ofthe closed portion of the leer. As previously stated, the rolls beyondthe closed section at the discharge end of the leer are first the idlerrolls- 21, and then the manually controlled power driven rolls 22, theoperation of which has already been described, and which will not beincluded in the following discussion.

Referring to Fig. 6, the rolls of the first ten sections of the leer areindicated by roman numerals I to X, inclusive, as the operation of thesesections is somewhat different from the remaining sections beginningwith the eleventh section and extending to the end of the closed portionof the leer. These latter sections during normal operation of the leerrotate successively forward and rearward controlled by their respectivesolenoids 57, which in turn are controlled by the timer switch A.

At the entrance to the open portion of the leer is the switch arm 79,which as shown in Fig. 8 is pivoted intermediate its ends as at 135,whereby, when a sheet of glass enters section I the line 80 will bebroken at 136.

The second switch arm 81 is located near the entrance to the closedportion of the leer, and closes the circuit 80 at 137 only when the arm81 is raised by contact with a sheet of glass, the line 80 beingnormally open at this point.

The first or primary section of rolls I rotates forwardly only and hasno solenoid for controlling its operation, this set of rolls beingconstantly operated from the main drive shaft. Rolls II to VIII,inclusive, are provided with solenoids which are controlled by both theswitches 79 and 81, and the rolls IX and X are controlled by the switch81 alone. The rolls II to X inclusive may be termed the transfer rolls,as their function is to transfer a sheet of glass from the primary setof rolls I which rotates constantly forwardly to the secondary rolls,which comprise most of the leer and extend from the eleventh section on,and which are periodically reversing in direction of rotation. Thesetransfer rolls are necessary to prevent buckling of the sheets, whichwould occur if a sheet were passed directly from the forwardly rotatingrolls to the reversing rolls. The transfer rolls may be automaticallysynchronized with the primary or constantly rotating rolls, and thenwith the secondary or reversing rolls.

Beforethe first sheetof glass is delivered to the leer the switch 79 isclosed while the switch 81 is open. the first ten sections are rotatingforwardly only, while the rolls in the remaining portion of the leer arerotating successively forwardly and rearwardly. When the first sheetenters section I the switch 79 is opened, which, however, does notchange the operation of the first ten sections of rolls, as the circuitis already opened by switch 81. The sheet continues to advance forwardlyuntil its rear end passes from under switch 79, and subsequently thefront end closes switch 81. Thus the line 80 is completely closedallowing current to pass from the main line lead 143 at 138 throughwires 80, 139, 140, 141, 142, switch 145 and from conductor 144 througha conductor 144' to the main line lead 143. A magnetic relay is providedin conductor 140 at 144 by means of which when switch 81 is closedswitch 145 noids 57 of roll sections II to VIII inclusive, whereby therolls of these seven sections are Therefore, the rolls of synchronizedwith the rest of the leer and rotate successively forwardly andrearwardly. Likewise the rolls of the ninth and tenth sections rotate inthe same manner in synchronism with the rest of the leer, a circuit frommain lead 143 having been closed by means;

of switch 81 through wire 170, timer 171, relay 172, and throughconductor 172' to the main lead 143. The energization of relay 172closes switch 146, thus completing the circuit from the emergencycontrol C, from one side of the supply line through wires 17 3 and I tothe other side of the is moving forwardly and rearwardly on the transferrolls. As 'soon'as the front end of the second sheet reaches switch'79sections wardlyonly.

circuit is closed.

II to VIII inclusive are caused to'rotate for- This movement continuesuntil the rear end of the second sheet has passed from under-switch 79,whereupon the This would cause therolls in sections II to VIII tocommence the reversing movement, except for the fact that the intervalbetween the pouring. of the first and second sheets iss such thatby thistime the rear end of the first sheet has passed-from under switch 81,thus breaking the circuit at this point and causing the rolls insections II to VIII to rotate-forwardly only. Sections IX and'X alsotake up this forward movement after a delayed interval, which allows thefirst sheet to-pass entirely from these two sections, the delayedaction'being due to the timbr 171, which controls the solenoids ofsections IX and X, this timer being connected to the negative line 143'by means of wires 18Q, 181 and 182,"as shown, and through relay 172,wires 173 and 174 and,associated-relays143 to the solenoids of saidsections and to the positive line 143. When the front end of the secondsheet reaches the switch 81 sections II to X, inclusive, take up thereversing movement in synchronism with the rest of the leer, Thissynchronism of the transfer rolls with the constantly forwardly movingrolls of the first section and then with the reversing rolls in theremainder of the leer continues as-each additional sheet of glass is fedup unless the operationv is varied by the action ofthe emergency controldevice, as

hereinbefore described.

' Fromthe foregoing description, it will be seen that in the operationof the apparatus the glass sheet passes first onto a series of rollsrotating in a forward direction only at a determined peripheral speed,which is at least as great as that of the speed of sheet formation whenthe leer is operatively coupled to a sheet glass casting device, whilethe rollers in the principal portion of the leer are revolving.successively forwardly and then rearwardly, but at the same peripheralspeed as the rolls which move. forwardly only.

These alternately reversing rolls normally rotate in a forward directionfor a longer eriod than in vthe rearward direction, in. order that theremay be a general advance of the sheet through the leer as a whole. Bythe use of the transfer rolls which transfer to the solethe sheetofbreaking or buckling of the direction ward direction, thusestablishing a differ-- through a treatment lass fromthe forwardlymoving rollsto t e reversing rolls any danger of sheet of glass isprevented As stated, these alternately reversing rolls normally rotatein a forward for a longer period tha li in the rearential action inorder that there may be, with a decreased rate of progress,'-a'generalad-' vance of the sheet through the leer as a whole. The purpose ofperiodically reversing the direction of movement of the rolls within theleer while maintaining a predetermined peripheral speed of rotation ofall the rolls is to obtain a maximum annealing effect for I0. givenlength ofv leer or the travel of the glass through an annealing courseof greater length than the'length of the leer as a whole,-

without necessarily slowing up the speed 0 rotation of the rolls at thetime they are'actmg on a sheet and thereby permitting the glass to sagbetween the rolls and causing deformation ofthe rolls themselves due toslow rotation. i v

It is, of course, not necessary that in the use of the apparatus forannealing sheet glass to have the glass p'aratus coupled to the rollerleer as the glass sheets may be formed by a separate mechanism andintermittently fed through suitable intervening means to the rolls 17 ofsection 18 of the leer for travel through the leer to obtain theannealing action described. The principle of the invention may also beapplied to the annealing of glassware, porcelainware, or ceramicwaresuitably formed and placed upon the roller leer for transport, as byarranging the articles in trays or other receptacles placedintermittently at the predetermined intervals upon the rollers 17 of theleer section 18 fortransmission through the-leer. The apparatus mayalsobe used for the transportation of bars, billets or other elements'or artic'lesrwhich are to be fed course for tempering or otherpurposes, as well as for drying purposes in the drying of variousmaterials or for coating of materials and other similar formed by aforming P Y of prohibitive length. It is to be understood that theoperations of the sets of rolls in the direction of feed of the materialmay be reversed, that is to say, that the first set of rolls or anynumber of sets of rolls in the preliminary traverse .of the material maybe reversing rolls, to give a slow rate of progress, while the rollsconveying the material on its final stage of traverse may movecontinually in one direction to give the material a high I catematerials or to delicate sur aces thereofliable to be damaged byirregular actions.

Within the scope of the invention, also, conveyer units of other thanroller type may possibly in some cases be used, particularly in thehandling of certain materials and by the employment of conveyer units ofrestricted length.

Having thus fully described my invention, I claim:

1. In an electric control system for conveyers, a roller con-veyer,driving means for the rolls of the conveyer, and automatic electricallycontrolled means governing the driving means for causing the same toperiodically and differentially rotate the rolls alternately forward andbackward.

2. In an electric control system for con-- veyers, primary and secondarysets of conveyer rolls, driving means for normally ro tatingboth sets ofrolls, means for reversing the secondary set of rolls, and automaticelectrically controlled means governing the driving and reversing means,for periodically causing said driving and reversing means to cause thesecondary rolls to differentially revolve forwardly and rearwardly.

3. In an electric control system for conveyers, a primary set ofconveyer rolls, a secondary set of conveyer rolls, a set of transferrolls between the primary and secondary sets of comeyer rolls, drivingmeans for all the rolls, and electrical means governing the drivingmeans to cause the primary set of rolls to constantly rotate in aforward di- F rection, the secondary and transfer rolls to periodicallyrevolve in a forward direction and then in a backward direction, and thetransfer rolls to synchronize successively with the primary rolls andthe secondary rolls.

4. In an electric control system for conveyers, a conveyer comprisingsets of rolls, roll driving and reversing means, and automaticelectrically controlled governing means controlling said driving andreversing means and acting thereon to cause the rolls of one set toconstantly rotate in one direction and to periodically cause the rollsof the other set or sets to rotate first in one direction and then torotate in the opposite direction, respectively, for different timeperiods.

5. In an electric control system for conveyers, a conveyer comprising aplurality of rolls, driving and reversing means for the rolls, andautomatic electrically controlled means governing the driving andreversing means and acting thereon to cause the same to drive all therolls at a common speed and to rotate a group .of the rolls constantlyin one direction and to periodically and for different time periodsrotate a following group of the rolls first in one direction and then inthedreverse direction for different time per1o s.

6. In an electric control system for conveyers, a conveyer comprising aprimary set of rolls, a secondary set of rolls, and transfer rollsbetween the primary and secondary rolls, driving and reversing means forthe rolls, and electrically controlled governing means controlling saiddriving and reversing means to cause the same to drive the primary setof rolls in a forward direction, to drive the secondary rollsalternately differentially forwardly and rearwardly, and to cause thetransfer rolls to rotate first in the same direct-ion'as the primary setof rolls a and then in the opposite direction with the secondary set ofrolls.

7. In an electric control system for conveyers, a plurality of conveyerrolls, driving and reversing means for the rolls, and time controlledautomatic electrical governing means controlling the driving andreversing means for producing an action of the rolls on an article beingconveyed thereby such as to cause the article to be periodically shifteddifferentially backwardly and forwardly by the rolls along a definiteportion of the conveyer so as to travel during a definite period of timea distance backwardly and a greater distance forwardly: L

8. In an electrical control system for conveyers, a primary set ofconveyer rolls constantly rotating in a forward direction, a secondaryset of conveyer rolls arranged in groups, means for periodically causingsome of the rolls to rotate in a forward direction and some to rotate ina rearward direction, the period of forward rotation of the rolls beinggreater than that of the rearward rotation of the rolls, a set oftransfer rolls arranged between the primary and secondary rolls androtating alternately for periods driving means for rotating all therolls, and

electrical means for controlling the rolls to operate as set forth.

9. In an electric control system for conveyers, a roller conveyer, meansfor driving all the rolls of the conveyer, and electrically controlledautomatic means governing the driving means for periodically effecting areversal of rotation of rolls at a plurality of points along theconveyer in the path of travel of an article being transporteed by theconveyer for a time period to cause the article to periodically travelbackwardly and for-

